Inspections
| Action
|
DEFINITION: Momentary lack of response as the accelerator is pushed down. Can
occur at any vehicle speed. Usually more pronounced when first trying to make the
vehicle move, as from a stop. May cause the engine to stall if severe enough.
|
Preliminary
|
| • | Inspect the powertrain control module (PCM) grounds for being clean,
tight, and in the proper locations. Refer to
Engine Controls Schematics
. |
|
Sensor/System
| Test the manifold absolute pressure (MAP) sensor operation. Refer to
Manifold Absolute Pressure Sensor Diagnosis
.
|
Fuel System
|
| • | Inspect both fuel injector fuses for being open. An open injector fuse
causes four ignition coils and four injectors not to operate. Replace the fuse. Inspect
the ignition coil circuits and the injector circuits for an intermittent short
to ground. |
| • | Inspect the following that may cause the engine to run rich: |
Notice: Refer to Heated Oxygen and Oxygen Sensor Notice in the Preface section. | - | Water intrusion in the HO2S connector |
| - | Engine oil contaminated by fuel |
| - | An evaporative emission (EVAP) canister purge condition |
| - | Vacuum hoses for splits, kinks and proper connections |
| • | Inspect the following that may cause the engine to run lean: |
Notice: Refer to Heated Oxygen and Oxygen Sensor Notice in the Preface section. | - | Water intrusion in the HO2S connector |
| - | An exhaust leak between the HO2S and the engine--Refer to
Exhaust Leakage
in Engine Exhaust. |
| - | Vacuum hoses for splits, kinks and proper connections |
|
Ignition System
|
| • | Wet down the secondary ignition system with water from a spray bottle.
Wetting down the secondary ignition system may help locate damaged or deteriorated
components. Look and listen for arcing or misfiring as you apply water. |
| • | An improper spark plug gap will cause a driveability problem. Gap the
spark plugs using a wire gage gap tool. Refer to
Spark Plug Replacement
. |
| • | Determine the cause of the fouling before replacing the spark plugs
if the spark plugs are gas, coolant, or oil fouled. Refer to
Spark Plug Inspection
for diagnosis of fouled spark plugs. |
| • | Monitor the Misfire Current Counters while driving the vehicle in the
conditions that the misfire occurred. If a cylinder can be located with a misfire,
refer to
Electronic Ignition (EI) System Diagnosis
for diagnosis. |
|
Engine Mechanical
| Inspect for excessive crankshaft endplay that will cause the CKP sensor reluctor
wheel to move out of alignment with the CKP sensor. Refer to
Crankshaft and Bearing Cleaning and Inspection
in Engine Mechanical -
8.1L. This could result in any of the following conditions:
|
Engine Cooling System
| Inspect the engine thermostat for proper operation and for proper heat range.
Refer to
Thermostat Diagnosis
in Engine
Cooling.
|
Additional
| Test the generator output voltage. Refer to
Diagnostic System Check - Engine Electrical
in Engine Electrical.
|
